using System;
using UnityEngine;

namespace FidelityFX
{
    /// <summary>
    /// All the compute shaders used by the FidelityFX Super Resolution 3 (FSR3) Upscaler.
    /// </summary>
    [Serializable]
    public class Fsr3UpscalerShaders: ScriptableObject
    {
        /// <summary>
        /// The compute shader used by the luminance pyramid computation pass.
        /// </summary>
        public ComputeShader computeLuminancePyramidPass;

        /// <summary>
        /// The compute shader used by the previous depth reconstruction pass.
        /// </summary>
        public ComputeShader reconstructPreviousDepthPass;

        /// <summary>
        /// The compute shader used by the depth clip pass.
        /// </summary>
        public ComputeShader depthClipPass;

        /// <summary>
        /// The compute shader used by the lock pass.
        /// </summary>
        public ComputeShader lockPass;

        /// <summary>
        /// The compute shader used by the accumulation pass.
        /// </summary>
        public ComputeShader accumulatePass;

        /// <summary>
        /// The compute shader used by the RCAS sharpening pass.
        /// </summary>
        public ComputeShader sharpenPass;

        /// <summary>
        /// The compute shader used to auto-generate a reactive mask.
        /// </summary>
        public ComputeShader autoGenReactivePass;

        /// <summary>
        /// The compute shader used to auto-generate a transparency & composition mask.
        /// </summary>
        public ComputeShader tcrAutoGenPass;
        
        /// <summary>
        /// Returns a copy of this class and its contents.
        /// </summary>
        public Fsr3UpscalerShaders Clone()
        {
            return (Fsr3UpscalerShaders)MemberwiseClone();
        }

        /// <summary>
        /// Returns a copy of this class with clones of all its shaders.
        /// This can be useful if you're running multiple FSR3 Upscaler instances with different shader configurations.
        /// Be sure to clean up these clones through Dispose once you're done with them.
        /// </summary>
        public Fsr3UpscalerShaders DeepCopy()
        {
            Fsr3UpscalerShaders copy = CreateInstance<Fsr3UpscalerShaders>();
            copy.computeLuminancePyramidPass = Instantiate(computeLuminancePyramidPass);
            copy.reconstructPreviousDepthPass = Instantiate(reconstructPreviousDepthPass);
            copy.depthClipPass = Instantiate(depthClipPass);
            copy.lockPass = Instantiate(lockPass);
            copy.accumulatePass = Instantiate(accumulatePass);
            copy.sharpenPass = Instantiate(sharpenPass);
            copy.autoGenReactivePass = Instantiate(autoGenReactivePass);
            copy.tcrAutoGenPass = Instantiate(tcrAutoGenPass);
            return copy;
        }

        /// <summary>
        /// Destroy all the shaders within this instance.
        /// Use this only on clones created through DeepCopy.
        /// </summary>
        public void Dispose()
        {
            Destroy(computeLuminancePyramidPass);
            Destroy(reconstructPreviousDepthPass);
            Destroy(depthClipPass);
            Destroy(lockPass);
            Destroy(accumulatePass);
            Destroy(sharpenPass);
            Destroy(autoGenReactivePass);
            Destroy(tcrAutoGenPass);
        }
        
        #if UNITY_EDITOR
        private void Reset()
        {
            computeLuminancePyramidPass = FindComputeShader("ffx_fsr3upscaler_compute_luminance_pyramid_pass");
            reconstructPreviousDepthPass = FindComputeShader("ffx_fsr3upscaler_reconstruct_previous_depth_pass");
            depthClipPass = FindComputeShader("ffx_fsr3upscaler_depth_clip_pass");
            lockPass = FindComputeShader("ffx_fsr3upscaler_lock_pass");
            accumulatePass = FindComputeShader("ffx_fsr3upscaler_accumulate_pass");
            sharpenPass = FindComputeShader("ffx_fsr3upscaler_rcas_pass");
            autoGenReactivePass = FindComputeShader("ffx_fsr3upscaler_autogen_reactive_pass");
            tcrAutoGenPass = FindComputeShader("ffx_fsr3upscaler_tcr_autogen_pass");
        }

        private static ComputeShader FindComputeShader(string name)
        {
            string[] assetGuids = UnityEditor.AssetDatabase.FindAssets($"t:ComputeShader {name}");
            if (assetGuids == null || assetGuids.Length == 0)
                return null;

            string assetPath = UnityEditor.AssetDatabase.GUIDToAssetPath(assetGuids[0]);
            return UnityEditor.AssetDatabase.LoadAssetAtPath<ComputeShader>(assetPath);
        }
        #endif
    }
}